Performance and stability improvements on all platforms.

TBR=v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com

Change-Id: I5847bae491a0f18f78478d6dee084d73c2a6773e
Reviewed-on: https://chromium-review.googlesource.com/c/1368466
Reviewed-by: v8-ci-autoroll-builder <v8-ci-autoroll-builder@chops-service-accounts.iam.gserviceaccount.com>
Cr-Commit-Position: refs/heads/7.3.70@{#1}
Cr-Branched-From: 62d3ea840c84c8cbd718bd74627d642e2f9c1cc2-refs/heads/master@{#58108}